Layer-specific input to distinct cell types in layer 6 of monkey primary visual cortex
Layer-specific input to distinct cell types in layer 6 of monkey primary visual cortex
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DOI：
10.1523/jneurosci.21-10-03600.2001
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发表时间：
2001-05-15
影响因子：
5.3
通讯作者：
Callaway, EM
中科院分区：
文献类型：
--
作者：
Briggs, F;Callaway, EM
猴V1的第6层包含生理上和解剖学上不同的兴奋性锥体神经元种群。在功能特化的皮质层中，轴突和树突的独特树突模式定义了八种类型的第6层锥体神经元，并表明每种细胞类型具有独特的信息处理作用。为了解决输入源如何促进细胞功能，我们使用扫描激光光刺激检查了单个第6层锥体神经元的功能性兴奋输入的层流源。我们发现兴奋性输入源与细胞类型相关。轴突突有选择性地靶向大细胞(M)受体层4C α的I类神经元接收来自M主导层4B的输入，而轴突突靶向parvocellular (P)受体层4C β的I类神经元接收来自P主导层2/ 3的输入。令人惊讶的是，这些类型的神经元在直接从4C - α或4C - β层接收的输入上并没有显著的差异。II类细胞在4C层内缺乏密集的轴突乔木，通过局部轴突接收来自层的兴奋性输入。具体来说，IIA型细胞将轴突投射到深层而不是浅层，并接受来自深层的输入。IIB型神经元投射和接收来自最深层和最浅层的输入，而不是中间层。IIC型神经元分布于整个皮质层，并倾向于接受来自所有皮质层的输入。这些观察结果对不同类型的第六层细胞在视觉信息处理中的功能作用具有启示意义。
Layer 6 of monkey V1 contains a physiologically and anatomically diverse population of excitatory pyramidal neurons. Distinctive arborization patterns of axons and dendrites within the functionally specialized cortical layers define eight types of layer 6 pyramidal neurons and suggest unique information processing roles for each cell type. To address how input sources contribute to cellular function, we examined the laminar sources of functional excitatory input onto individual layer 6 pyramidal neurons using scanning laser photostimulation. We find that excitatory input sources correlate with cell type. Class I neurons with axonal arbors selectively targeting magnocellular (M) recipient layer 4C alpha receive input from M- dominated layer 4B, whereas class I neurons whose axonal arbors target parvocellular (P) recipient layer 4C beta receive input from P- dominated layer 2/ 3. Surprisingly, these neuronal types do not differ significantly in the inputs they receive directly from layers 4C alpha or 4C beta. Class II cells, which lack dense axonal arbors within layer 4C, receive excitatory input from layers targeted by their local axons. Specifically, type IIA cells project axons to and receive input from the deep but not superficial layers. Type IIB neurons project to and receive input from the deepest and most superficial, but not middle layers. Type IIC neurons arborize throughout the cortical layers and tend to receive inputs from all cortical layers. These observations have implications for the functional roles of different layer 6 cell types in visual information processing.